Graduate Theses & Dissertations

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Neolithic Resource Use and Adaptation in the Eastern Gobi Desert
Stone axes and adzes first appeared in the eastern Gobi Desert at 8.0 cal BP and were incorporated into the technological package. At the same time, changes in local ecological conditions reflect a transition from continuous grass/shrub-steppe across the Mongolian Plateau to the development of dispersed patches of dune-field wetland oases and high-elevation forests. This thesis focuses on exploring the adoption and function of axes and adzes in the eastern Gobi Desert and their relationship to the development of these new forested ecologies. Using an experimental and use-wear approach, I analyze 29 axes and adzes from four sites in the eastern Gobi Desert of Mongolia and Inner Mongolia. Results indicate that axes and adzes were primarily used for woodworking but include other activities. Furthermore, the adoption and manufacture of axes and adzes represent an increasing investment in producing formal technologies as resources within these new diverse ecological patches were intensively utilized. Author Keywords: Adaptation, Axes and Adzes, Eastern Gobi Desert, Neolithic, Technological Intensification, Use-Wear
Perceive Me, Perceive You
The use of threats to feelings of intimacy and belonging, also known as relational aggression, has been previously explained using attachment representations and attributions in childhood. However, the combined role of attachment representations and attributions in explaining relational aggression in adult peer and romantic relationships has been unexplored. This study tested the associations between attachment, attributions, and relational aggression with a specific focus on the mediating role of attributions. A final sample of 258 undergraduate university students completed self-report surveys and vignettes to measure the variables of interest. Results suggested that attachment predicted relational aggression but, with one exception, attributions did not explain unique variance in relational aggression after controlling for attachment. Interestingly, hostile attributions mediated the relationship between dismissing attachment to romantic partners and romantic relational aggression. Therefore, individuals‘ attachment representations directly influenced their levels of relational aggression in relationships regardless of their attributions. Author Keywords: Adulthood, Attachment, Attributions, Mediation, Relational Aggression
Fingerprinting of dissolved organic matter and copper ligands in the Canadian Arctic and North Pacific Ocean
Dissolved organic matter (DOM) in oceans provides nutrients and ultraviolet radiation protection to microbes. Some DOM compounds can chelate with metals, including copper, controlling their transport and bioavailability in marine systems. As copper functions as both a nutrient and toxicant, studies into the chemical structures of Cu-ligands is important, however currently limited. In this thesis, the chemical composition of total and Cu-binding DOM is investigated using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in the Canadian Arctic and North Pacific. Chapter 2 reveals chemical differences in DOM composition between the southern and northern Canada Basin, revealing the influence of terrestrial and biological sources. Chapter 3 shows the uniqueness of Cu-binding ligands found in the Canadian Arctic and North Pacific Ocean. Studying the composition of DOM gives insight into the chemical diversity of marine DOM, helping to predict the effects of a changing climate on marine ecosystems. Author Keywords: biological, dissolved organic matter, fluorescence, immobilized metal-ion affinity chromatography, mass spectrometry, terrestrial
Indigenous Knowledge in Contemporary Public Education
This study provides important perspectives and guidance for educators in Ontario to assist in integrating Indigenous content into public education programs – both in schools and other community educational settings. It explores how Indigenous worldviews provide unique insights for holistic education and learning how to live sustainably in place. The study also focuses on approaches to education, comparing Eurocentric and Indigenous philosophies and pedagogies, as indicators of differing value systems. Through a combination of literature review and personal interviews with eleven influential Indigenous and non-Indigenous educators in the Peterborough area, the study explores the potential for Indigenous perspectives to enhance the wellbeing and personal learning journey of all students, regardless of their backgrounds. The research concludes with recommendations for educators on how to begin integrating Indigenous Knowledge throughout programming in appropriate, respectful ways that celebrate diversity, develop positive relationships and build healthier, more sustainable communities. Author Keywords: Education, Environment, Indigenous Knowledge, Pedagogy, Reconciliation, Worldviews
Expression optimization and NMR spectroscopy of Giardia intestinalis cytochrome b5 isotype III
The parasitic protist Giardia intestinalis does not synthesize heme and lacks many common eukaryotic heme proteins, yet it expresses four cytochrome b5 (gCYTB5) isotypes of unknown function. These have low reduction potentials and distinct subcellular locations that are consistent with structural features and biological functions that differ from their mammalian counterparts. Isotype III (gCYTB5-III) is particularly fascinating for its unusual location in the nuclei of Giardia. This thesis reports the optimization of recombinant gCYTB5-III overexpression for structural studies by NMR spectroscopy. Vital optimization factors for isotope labelling were first identified, finding that auto-induction promotes the optimization of many other conditions, such as colony selection, starter cultures, media components, temperature, pH and aeration. Optimized conditions were then applied to the expression and NMR spectroscopy of isotope-labelled gCYTB5-III and bovine cytochrome b5 as a control. These results can be extended to other heme proteins and will expand our biochemical knowledge of Giardia. Author Keywords: Auto-induction, Cytochrome b5, Giardia intestinalis, Isotope Labelling, Nuclear Magnetic Resonance Spectroscopy, Recombinant Protein
“It's like getting a new car without the manual”
This study explored teacher infusion of Indigenous curriculum content through interviews with ten non-Indigenous teachers of social studies and history. The interviews centered on teacher perceptions of preparedness to implement Ontario’s recent TRC curriculum revisions, which include more about the contributions, histories, cultures, and perspectives of Indigenous peoples. A brief analysis of Ontario’s First Nation, Métis, and Inuit Education Policy Framework is included, alongside critiques of the Eurocentrism at the heart of education systems. The interviews revealed that many of the teachers were committed to Indigenous education and learning more, but they felt unprepared and lacked resources to teach Indigenous curriculum content with confidence. This study highlighted the critical role of settler teachers in Indigenous education and the importance of teachers undertaking settler unsettling in order to be effective and appropriate in Indigenous curriculum delivery. Individual changes must occur alongside educational system decolonization with a particular focus on teacher preparation. Author Keywords: cognitive imperialism, Indigenous Education, Ontario, settler educator, settler unsettling, TRC curriculum
Detectability and its role in understanding upland sandpiper (Bartramia longicauda) occurence in the fragmented landscape of southern Ontario
Upland Sandpipers (Bartramia longicauda), like many grassland birds, are undergoing population decline in parts of their range. Habitat fragmentation and change have been hypothesized as potential causes of decline. I used citizen-science occurrence data from Wildlife Preservation Canada’s Adopt-A-Shrike Loggerhead Shrike (Lanius ludovicianus) program in conjunction with validation surveys, using similar point-count methods, to examine detectability and determine if landscape level habitat features could predict occupancy of Upland Sandpipers in Southern Ontario. In a single season detectability study, I used Wildlife Preservation Canada’s survey protocol to determine detectability in sites that were known to be occupied. Detectability was low, with six surveys necessary to ensure detection using a duration of at least 18 minutes early in the breeding season. The proportion of open habitat did not affect detection on the landscape. Using a larger spatial and temporal scale, with five years of citizen-science data, I showed that Annual Crop Inventory data could not effectively predict Upland Sandpiper occupancy. Model uncertainty could be attributed to survey protocol and life history traits of the Upland Sandpiper, suggesting that appropriate survey methods be derived a priori for maximizing the potential of citizen-science data for robust analyses. Author Keywords: Bartramia longicauda, citizen-science, detection, landscape, occupancy, Ontario
Modelling the Lanthanum Aluminate-Strontium Titanate Interface with a Modified Transverse Ising Model
In 2004 it was discovered that a two-dimensional electron gas (2DEG) forms at the interface between lanthanum aluminate (LAO) and strontium titanate (STO). This 2DEG exhibits a variety of electronic and magnetic phenomena, motivating intense research into its applicability to electronic devices. Over the years several models have been developed in theoretical exploration of this system. Here, the transverse Ising model is applied to the LAO/STO interface for the first time. It is shown that the model as it is traditionally formulated cannot accurately predict the structure of the electron density at the interface. I show that this can be fixed with a simple modification of the model, and discuss how this modification affects both the polarization distribution in ferroelectric thin films and the electron density at the LAO/STO interface. The importance of including the depolarizing field when modelling spatially inhomogeneous ferroelectric systems is also explored. Author Keywords: ferroelectric thin film, lanthanum aluminate, strontium titanate, transverse Ising model, two-dimensional electron gas
Support Vector Machines for Automated Galaxy Classification
Support Vector Machines (SVMs) are a deterministic, supervised machine learning algorithm that have been successfully applied to many areas of research. They are heavily grounded in mathematical theory and are effective at processing high-dimensional data. This thesis models a variety of galaxy classification tasks using SVMs and data from the Galaxy Zoo 2 project. SVM parameters were tuned in parallel using resources from Compute Canada, and a total of four experiments were completed to determine if invariance training and ensembles can be utilized to improve classification performance. It was found that SVMs performed well at many of the galaxy classification tasks examined, and the additional techniques explored did not provide a considerable improvement. Author Keywords: Compute Canada, Kernel, SDSS, SHARCNET, Support Vector Machine, SVM
Question of Space
Chultuns are subterranean chambers that are found throughout the Maya area. The purpose of this thesis is to provide further insight into the function of chultuns, specifically within the area of the Southern Maya Lowlands. Within the Northern Lowlands, the Pre-Columbian Maya used chultuns for water storage, but this function does not appear to be as prevalent within the Southern Lowlands Through reviewing published literature and first-hand excavation, a total of 332 chultuns located with the specified area were catalogued into a database. Based on the information obtained from the research, this thesis has identified the most frequent final function of chultuns, if there is chronological change in final functions of chultuns, and if there is regional change in final functions of chultuns. Author Keywords: burial, chultuns, Maya, ritual, Southern Lowlands, storage
Making eDNA count
Environmental DNA (eDNA) is rapidly becoming an established method for the detection of species in aquatic systems and has been suggested as a promising tool to estimate species abundance. However, the strength of the relationship between eDNA concentrations and taxon abundance (density/biomass) can vary widely between species. I investigated the relationship between eDNA concentration and species abundance using two common and closely-related amphibians in eastern North America, the wood frog (Rana sylvatica) and northern leopard frog (Rana pipiens). I manipulated tadpole density in 80 L mesocosms and documented the relationship between tadpole density, biomass, and eDNA concentration. Species were comparable in biomass but differed in the amount of detectible genetic material produced; density and biomass were the superior abundance metric correlated with eDNA concentration for wood frogs and leopard frogs, respectively. However, increases in eDNA concentration reflected increasing tadpole biomass, therefore biomass is likely a better metric of abundance than density. Overall my findings support that eDNA concentration can be used as an index of species abundance, but that species-specific calibration may be needed before eDNA concentration can be effectively translated to an abundance metric. Future research should refine our understanding of how biotic and abiotic factors influence eDNA production, degradation, and recovery across species, before the method can receive widespread use as a monitoring tool in natural settings. Author Keywords: abundance estimates, environmental DNA, mesocosm, Rana pipiens, Rana sylvatica
Observation-based assessment of atmospheric sulphur surrounding a major aluminum smelter in British Columbia, Canada
Recent developments at an aluminum (Al) smelter in Kitimat, BC resulted in a permitted increase of 27 to 42 tonnes of sulphur dioxide (SO2) emissions per day. Gaseous SO2 is a pollutant known to contribute to acidic deposition through processes of wet and dry deposition and can additionally react in-atmosphere to form particulate sulphate (pSO42-). Between June 2017 to October 2018, an extensive network consisting of ion exchange resin (IER) column, passive-diffusive, and active filter-pack samplers was established to provide an estimate of total annual S deposition and pSO42- variation throughout the Kitimat Valley. Filter-pack sampling determined the relative concentration of pSO42- increased downwind of the smelter. Comparison of observation-based and modelled total annual deposition suggested CALPUFF was accurate in representing the spatial viability of S deposition (R2 = > 0.85). However, the model appeared to overpredict near-field deposition suggesting the potential of underestimation further downwind of the smelter. Author Keywords: aluminum smelter, atmospheric deposition, filter-pack sampler, ion-exchange column sampler, pSO42-, SO2

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Format: 2020/10/31